The present invention relates to an optical coupling structure for optically coupling a plurality of optical components and a fabrication process of such an optical coupling structure. More particularly the present invention relates to an optical coupling structure carrying a plurality of optical components on a plurality of flat sub-mounts with an exact optical alignment between the optical components, which plurality of flat sub-mounts in turn being mounted on a flat substrate in an exact optical alignment.
In optical-fiber telecommunication networks or optical information processing systems, various optical apparatuses are constructed by assembling various optical components. For example, an optical source used in an optical fiber network includes a laser diode and a lens provided in an optical alignment with an optical fiber for injecting an optical beam produced by the laser diode into the optical fiber. On the other hand, there are optical systems for use in laser beam printers or optical disk drives, in which a laser diode is optically coupled to a lens or other optical components. Thus, there exists a persisting demand for a simple fabrication process of such optical apparatuses.
Generally, there are two known types of optical coupling structures for achieving a desired optical coupling of optical components on a flat slab member, which will be referred to hereinafter as a "substrate."